Interactive respiratory regulator

ABSTRACT

An interactive respiratory regulator comprising a recording device recording the respiratory pattern of a user and issuing a corresponding respiratory signal, an instruction signal generator for the generation of an instruction signal that can be perceived by the user in order to influence his respiratory behavior, a control device controlling the instruction signal generator, a processing device which determines by means of a parameter of the respiratory signal received, whether the recorded respiratory pattern during a predetermined time span meets a pre-adjustable standard for this parameter, and which at a certain error percentage sends a starting signal to the control device. The interactive respiratory regulator is characterized in that the processing device processes as parameter the ratio between the in- and exhalation time in a respiratory cycle. In a preferred embodiment the processing device includes the frequency of the respiratory cycles as second parameter and the pre-adjustable standard comprises also a value for this parameter.

REFERENCE TO RELATED APPLICATION

This application is a Continuation-in-part of U.S. application, Ser. No.08/491,946 filed Aug. 30, 1995 now U.S. Pat. No. 5,730,145 entitled AnInteractive Respiratory Regulator.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to an interactive respiratory regulatorcomprising:

a recording device recording the respiratory pattern of a user andproducing a corresponding respiratory signal,

an instruction signal generator for generating an instruction signalthat can be perceived by the user in order to influence his respiratorybehavior,

a control device controlling the instruction signal generator,

a processing device which determines by means of a parameter of therespiratory signal received whether the respiratory pattern recordedduring a predetermined time span meets a pre-adjustable standard forthis parameter, and which at a certain error percentage sends a startingsignal to the control device.

2. Description of Related Art

An apparatus of this kind, indicating to a user a desirable respiratorypattern, is known from the Netherlands patent specification 166.850,whereby this apparatus, In particular to combat the hyperventilationsyndrome, is provided with a device for determining the cycle time. Thecorresponding frequency of the respiratory cycles is applied asparameter for the respiratory pattern. The recording device, being forinstance a strain gauge or a mercury wire recorder applied to the chestof the user, produces a pulse signal with a repeat frequencycorresponding with the respiratory frequency. This signal is fed to atime-determining device which compares this frequency with a presentstandard or limit value. As soon as this processing device determinesthat the respiratory frequency is higher than the limit frequency itwill set off a sound generator which during each respiratory cycleproduces two, for the patient audible and differentiable tones.

However, not only patients suffering from hyperventilation, the symptomof which is an abnormally high respiratory frequency, exhibit anon-optimal respiratory behavior, but also users who suffer, forinstance, from phobias or psychic traumas of any kind.

Describing the pattern of such a non-optimal respiration solely in termsof respiration frequency was shown not always to be adequate. Thepresent invention ensues from the search for a useful, instructivefeedback to the user with non-optimal respiratory patterns includingothers besides those which occur through hyperventilation. On thesegrounds it has been concluded that in order to analyze a respiratorypattern correctly, knowledge of especially the ratio between the in- andexhalation times is indispensable. The pause after exhalation is also animportant parameter.

The known apparatus described above has, however, the limitation that itdoes not include that necessary extra information in the feedbackprocess, thus offering insufficient possibilities for application toremedy disorders or to correct deficient respiratory patterns ingeneral.

SUMMARY OF THE INVENTION

The object of the invention is to provide an apparatus in accordancewith the kind mentioned in the preamble, which analyzes a user'srecorded respiratory pattern in more detail and which not only tests athreshold with respect to the respiratory frequency.

To this end the interactive respiratory regulator according to theinvention is characterized in that the processing device processes asparameter the ratio between the in- and exhalation time in a respiratorycycle, and optionally the pause after exhalation.

In a preferred embodiment the processing device includes the frequencyof the respiratory cycles as a second parameter and the pre-adjustablestandard also comprises a value for this parameter.

This apparatus can offer the user suffering from any kind of stressdependant respiratory regularity disorders the advantage of usefulfeedback. Thus, the apparatus offers a wide range of applicability notonly with hyperventilation, but in principle with any non-optimalrespiratory behavior. The interactive respiratory regulator can, forinstance, also be used by people who, especially in the case ofcontinual stress, wish to acquire a healthy manner of respiration.

The invention also relates to a recording device for the recordal ofmovements of parts of the body, particularly for the use in aninteractive respiratory regulator according to the invention. Therecording device is characterized in that the respective parameter errorsignals are fed to a decision device, the output signal of which is fedto the control device as a starting signal.

Preferably the recording device determines the values of the variousparameters of the movement pattern from the frequency changes of thesound impulses during each cycle of movement. In this way the system canput into practice effectively, without sensitivity to interferences andwith a very short setting time, without adjusting the length of the tubeto the circumference of the user's chest.

The interactive respiratory regulator according to the invention will bedescribed below on the basis of an embodiment example referring to theaccompanying drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a general block diagram of a preferred embodiment of theinteractive respiratory regulator in accordance with the invention.

FIG. 2 is a block diagram of the recording device of FIG. 1.

FIG. 3a is an amplitude-time diagram of the respiratory signal of FIG. 1produced by the recording device.

FIG. 3b is an example, very schematically illustrated, of afrequency-time diagram of the instruction signal emitted by theinstruction signal emitted by the instruction signal generator.

FIG. 4 is a block diagram of the processing device of FIG. 1.

FIG. 5 is a block diagram corresponding to FIG. 1 comprising in additionan operating device and display unit.

FIG. 6 is a schematic frontal view of the recording device.

FIG. 7 is an illustration of a recording device applied to a user'schest.

FIG. 8 is a graphic representation of the number of respirations perminute plotted against the ratio of the in- and exhalation time fordifferent groups of users.

DESCR IPTION OF THE PREFERRED EMBODIMENT

As shown in FIG. 1 the interactive respiratory regulator 1 comprises arecording device 2, recording the user's respiratory movement andtransducing this into an electrical, for instance digital respiratorysignal 3, which is fed into a processing device 4.

In this processing device 4 the characteristic parameters such as cycleduration, the ratio between the in- and exhalation time during arespiratory cycle and optionally the pause after exhalation of therespiratory signal 3 thus received are then determined and compared withstandard values that have previously been programmed into a memory 5 andcan be read via a data path 6. If during a predetermined time span oneor more parameters do not come up to the standard values, the processingdevice 4 will, at a certain maximal error percentage, send a startingsignal to control device 7. This control device 7 is also connected tothe memory 5 and is, just as the processing device 4, controlled by aclock signal sent by the clock generator 8.

Via a data path 9 the control device 7 reads information, correspondingto the standard values from the memory 5 and feeds these via a data path10 into an instruction signal generator 11. From this information saidgenerator then compiles an optimized respiratory pattern which serves toinstruct the user with the object of influencing his respiratorybehavior.

This optimized respiratory pattern is issued in the form of aninstruction signal 12, for instance a sound signal conveyed via aheadphone 13. This can, for example, consist of two. distinguishabletones of different pitch per respiratory cycle, as is illustrated veryschematically in FIG. 3. If the user follows these respiratoryinstructions, the corrected respiratory behavior will eventually lead toa desired improvement of his physiological condition. As soon as therespiratory pattern, which is constantly recorded by the recordingdevice 2, once more meets the above-mentioned parameter standards, theprocessing device 4 will remove the starting signal to the controldevice 7, when the generator 11, possibly after a certain delay orlearning period, will stop issuing the instruction signal 12.

The recording device 2 which is shown schematically in FIG. 2, comprisesin a special embodiment an elastic hollow tube 14, stretched around thechest or abdomen of the user, forming the measuring distance of therecording device 2. At the two ends of the tube 14 electro-acoustictransducers 15, 16 are mounted to generate, respectively receive, soundimpulses transmitted through the tube 14. The sound impulse sender 15transduces electrical signals 18 emitted by an impulse generator 17 intosound impulses which in a certain transit time pass through the lengthof tube 14 and are subsequently received by the receiver 16. Saidreceiver then transduces the sound impulses into electrical signals 19,which are fed back preferably via a frequency regulation device 20 tothe impulse generator 17. This feed-back, preferably in the form of aphase-locked loop, occurs such that the repeat frequency f of the soundimpulses is inversely proportional to the length L of the tube 14. Thusthe length of the tube 14 can be directly deduced from this soundimpulse frequency and consequently also the changes therein caused bythe respiratory movements of the user.

The transit time of the sound impulses is determined by the length ofthe tube 14, which will vary due to the respiratory movements. Duringone in- and exhalation, the length of the tube will increase,respectively decrease and consequently a sound impulse will be receivedat a relatively earlier, respectively later moment in time. The momentof reception is compared with a reference impulse signal 21 issuedsimultaneously by the impulse generator 17. The time and phasedifference with respect thereto is determined by a phase differencedetector 22, determining the extent of the phase difference as well asits character, that is to say, it will determine whether the impulsesignal 19 received lags behind the reference pulse signal 21(inhalation) or runs ahead of it (exhalation).

In order to guarantee a stable phase relation between the referenceimpulse signal 21 and the received pulse signal 19, in other words inorder to maintain the relation f-1/L, the repeat frequency f of thePulse signal produced by tale pulse generator 17 must be adjusted aftereach pulse cycle. This is preferably done, as already mentioned, bymeans of a phase-locked loop, to which end the frequency regulationdevice 20 is among other things equipped with a filter, an integratorand a voltage-controlled oscillator, which, however, for the sake ofsimplicity are not shown in the block diagram of FIG. 2. In this way thepulse frequency f of the electrical pulse signal generated by thegenerator 17 is regulated such that in case of a longer or shorterlength of tube 14 the pulse frequency f is lowered, respectively raisedby means of said regulation loop. In this manner the phase relationbetween the received signals and the reference pulse signals 19respectively 21 at the beginning of each pulse cycle are stabilized,irrespective of the extent to which the tube 14 is stretched.

In order to also keep the sound pulses, weakened by transmission lossesin the tube 14, at a constant intensity, independent of the length ofthe tube 14, the received pulse signal 19 is at the same time fed backinto the pulse generator 17 via an amplitude regulation device 23,effectuating a constant amplitude of the pulse signal.

It will be understood that the recording device 2 is completely selfadjusting so that it can be equipped with, for instance a removable andeasily deformable tube 14 of any length which does not need to beadapted to the chest circumference of the user. The tube 14 cantherefore easily be applied by the user himself, without any aids suchas adhesive, adhesive tape or adhesive electrodes, if desired even overthe clothing of the user. Exchange of the recording device 2 betweenusers, female or male, is also no problem. The electro-acoustictransducers 15, 16 can, for instance, be housed in a housing which canserve as coupling piece for connecting the ends of the tube 14 and thenecessary electric wiring.

The signal issued by the phase difference detector 22 is fed into arespiratory pattern analyzer 24 which by means of the phase differencesignal analyzes the recorded respiratory pattern, passing the same inthe form of a respiratory signal 2, for instance, in digital form as isshown in FIG. 3, to the processing device 4.

This processing device 4 is shown in a very simple basic form in FIG. 4.It comprises a cycle detector 30 which at the beginning of eachrespiratory cycle defined as the moment at which an inhalationcommences, issues a cycle pulse 31, resetting and starting a controlledcycle time counter 32 coming from the clock signal of the clockgenerator 8 (see FIG. 1). A cycle time comparator 33 compares constantlythe count T of the cycle counter 32 with a cycle time standard value c,read from the memory 5. As soon as T reaches the value c, the comparator33 issues a cycle time go-signal 34 which is fed into a time averagingdevice 35. During a preset period of time said device will determine theaverage and will feed this into a comparator 36, which, if this averagenumber is below a certain minimum percentage m, will issue a cycle timeerror signal 37.

In the lower branch of FIG. 4 the ratio between the in- and exhalationtime during each respiratory cycle is evaluated at the same time.

For this purpose there are preferably two frequency dividers 38 and 39included, which are both controlled by the clock signal with thefrequency F. During each inhalation the frequency divider 38, enabled bythe respiratory signal 3, issues a pulse signal with frequency F R/10,whereby R is a value read from the memory 5 equal to five times theratio's standard value r, to an adder entry of a ratio counter 40, whichis reset at the beginning of each cycle. On the other hand, thefrequency divider 39 enabled by the inverted respiratory signal 3 sendsduring each exhalation a pulse signal with frequency F/2 to a deductionentry of the ratio counter 40. When, after successively adding ordeducting the count of the ratio counter 40 has reached the value zero,that is to say as soon as the exhalation time is at least equal to theinhalation time multiplied by a factor r, then a ratio comparator 41,being in fact a zero detector, sends a ratio go-signal 42, resultingeventually via a time averaging device 43 and a comparator 44 in a ratioerror signal 45, if the average number of ratio errors is too high.

The cycle time and ratio error signals 37, 45 are fed to a decisiondevice 46, which, for instance carries out a logical or function andissues the starting signal if one or more error signals are active.

It will be clear to an expert in the field of electronic circuits thatthe principle described above can, of course, be carried out in manyother ways. Especially with the current microprocessor techniques theprocessing device 4 can in an alternative embodiment be provided with aprocessing unit with a memory in which a computer program is stored.This program can then determine in real-time the cycle time and theratio between the in- and exhalation time from the respiratory signal 3;can compare these parameters with selected standard values; can averagethe result of these comparisons over a predetermined time; and can causethe issue of a starting signal dependent on a predetermined decisioncriterium to the control device 7.

The interactive respiratory regulator 1 possesses at least two actionmodes, viz. a programming mode and a feedback mode. During the feedbackmode the recording device 2 records the respiratory pattern of the userand the instruction signal generator 11 sends him, if necessary,instruction signals 12. During the programming mode the instructionsignal generator 11 is blocked and the possibility exists to select viaan operating device 51 equipped with a keyboard 50, as shown in FIG. 5,a combination of one or more parameter conditions and a correspondingrespiratory pattern. These parameter standards and respiratory patterninformation are, as already mentioned, stored in the memory 5 andcorrespond with each other in the form of a number of series ofrespiratory patterns and parameter conditions specifically geared tothem. In this manner the user and/or the treating therapist may choosefrom a number of respiratory instruction programs, each of whichcomprises a respiratory pattern to be synthesized with the correspondingstandard values.

The respiratory pattern information stored In the memory 5 relates tothe in- and exhalation times, the in- and exhalation rate and/or thepauses following the in- and exhalations. These parameters are expressedby the instruction signal generator 11 in the form of changes in theduration and the pitch of the zone of the instruction signal 12.Particularly instructive is, for instance, a tone increasing in pitch toindicate an inhalation, respectively, a tone decreasing pitch toindicate an exhalation (see FIG. 3b).

To this purpose the control device 7 reads said information via a datapath 9 from the memory 5 and passes this via a data path 10 on to theinstruction signal generator 11. Said generator uses the information inthe feed back mode, if the starting signal is active, to synthesize thedesired respiratory pattern. Its characteristics are thus determined bychoice through the information selected from the memory with thekeyboard 50.

Data regarding the selected respiratory feed-back program can be shownduring programming, preferably via a display unit 52, illustrated inFIG. 5. This display unit 52 can also show, for instance during aspecial instruction mode, the parameters of the currently recordedrespiratory pattern for the purpose of an optical feedback to the useror for instance the therapist, to make a diagnosis.

In order finally to allow the user or the person susceptible to stressto become accustomed to the instruction signals, it is also possible toprovide a teaching mode. During this teaching mode the instructionsignal 12 is issued by the instruction signal generator 11 independentlyof the starting signal. The choice between the different modes is simplymade via the key board 50.

The display unit schematically shown in FIG. 6 comprises the housing 53in which the electro-acoustic transducers 15, 16 are housed. One ofthese electro-acoustic transducers 15, 16 functions as source, the otheras receiver unit. The electro-acoustic transducers 15, 16 are connectedwith each other via the elastic tube 14, which is made, for instancefrom silicone polymers. The connection between the tube 14 and theelectro-acoustic transducers 15, 16 can be made by means of the tubeconnectors 54, 55 mounted in the housing.

For securing to chest or abdomen with the aid of the tube 14, thehousing can be provided with a fastening notch 56, extending for exampleover 180° or more over the circumference of the housing.

As mentioned above, the electro-acoustic transducers 15, 16 may behoused in a housing. This housing may have the form of a clasp, wherebythe tube 14 is formed into a single large loop and is stretched doublearound the chest and/or abdomen. This is shown in FIG. 7, whereby thetube 14 is stretched in a double loop around a person's chest and thehousing 53 functions as clasp. The tube 14 is brought over an operabledistance into the fastening notch 56. The connecting lead 58 leads fromthe housing to the processing device 4 (not shown).

According to a favorable embodiment the interactive respiratoryregulator is executed in the form of an automatic device comprising acontrol program and predetermined standard values. Dependent on theuser, for example, in the case of children or patients such as stresspatients, trauma patients, one may deviate from the fixed standardvalues, the respiratory regulator exactly controls the respiration incorrespondence with the parameters (frequency, ratio, pause)incorporated in the standard values. This enables the user, without helpfrom a doctor or expert, to operate and use the respiratory regulator,which was not possible with the respiratory regulators according to theprior art.

In FIG. 8 the ratio R, being the inhalation time divided by theexhalation time, is plotted against the number of respirations perminute. This gives a different picture for different user groups. FieldA, indicated by a discontinuous line, comprises normal, healthy adultswhile field D, indicated by a continuous line, shows the level ofrespiration achieved by people going in for sports and yoga. Individualswith irregular respiration are found in field C, indicated by a dot-dashline. Individuals who hyperventilate are found in field S. For childrenwhose chests are not yet full-grown, a similar graph can be made. Thus,the apparatus according to the invention also allows a diagnosis Lo bemade. in addition, the apparatus can be used for therapeutic purposeswithout any further adaptations. Apart from regulating deficientrespiratory patterns the apparatus according co the invention was alsoshown to help people who, through traumatic experiences in the past andin spite of psychotherapy or relaxation exercises, were unable tobreathe in a healthy, regular manner, to breathe calmly and controlledwithin 5-10 minutes. In this way it was possible to achieve a deeprelaxation much faster than when using apparatuses according to theprior art, which has a very favorable effect on coping with psychictraumas.

We claim:
 1. An interactive respiratory regulator for a user having abody and a respiratory pattern and cycle possessing an inhalation andexhalation time having a ratio thereof, a pause being present afterexhalation, comprising:a recording device recording the respiratorypattern of a user and producing a corresponding respiratory signal, aninstruction signal generator for generating an instruction signal thatcan be perceived by an user in order to influence his respiratorybehavior, a control device controlling the instruction signal generator,a processing device which determines by means of a parameter of therespiratory signal received whether the respiratory pattern recordedduring a predetermined time span meets a preadjustable standard for thisparameter, and which at certain error percentage sends a starting signalto the control device,the processing device (4) processes as parameterthe ratio between the inhalation and exhalation time in a respiratorycycle, and optionally uses the pause after exhalation.
 2. An apparatusaccording to claim 1, whereby respiratory cycles have a frequency, thefrequency of the respiratory cycles is measured, wherein the processingdevice (4) processes the frequency of the respiratory cycles as secondparameter and that the pre-adjustable standard also comprises a valuefor this parameter.
 3. An apparatus according to claim 2, wherein therespiratory signal is fed to a clock generator controlled counter and acomparator, which during each respiratory cycle, when a countcorresponding with a parameter standard is reached, issues an outputsignal to a time averaging device, wherein the processing device (4) isprovided with at least two such counters (32, 40), comparators (33, 41)and time averaging devices (35, 43) allotted to each parameter, wherebyeach comparator (33, 41) sends a parameter O.K. signal (34, 42) to befed to a time averaging device (35, 43), as soon as the correspondingcounter (32, 40) has reached a count corresponding with the respectiveparameter standard.
 4. An apparatus according to claim 3, wherein thecounter (40), in order to compare the ratio between the inhalation andexhalation time with the standard, adds during an inhalation and deductsduring an exhalation.
 5. An apparatus according to claim 4, whereinduring a predetermined period of time each time averaging device (35,43) will determine a percentage of faulty respiratory cycles where therelevant parameter does not comply with the corresponding parameterstandard, and that each time averaging device (35, 43) is connected tocomparator (36, 44) recording any parameter error signal (37, 45) assoon as an average error percentage for that parameter exceeds a presetvalue.
 6. An apparatus according to claim 5, wherein respectiveparameter error signals (37, 45) are fed into a decision device (46),the output signal of which is fed into the control device (7) asstarting signal.
 7. An apparatus according to claim 6, wherein adecision organ (46) carries out a logical function.
 8. An apparatusaccording to claim 2, wherein the processing device (4) is provided witha processing unit having a memory, in which a computer program isstored, which on execution determines from the respiratory signal (3)the time of the cycle and/or the ratio between the inhalation andexhalation times in real-time, compares these parameters with (a)standard value(s) selected for this purpose, averages results of thesecomparisons over a predetermined period of time and causes a startingsignal to be sent to the control device (7), in accordance with apredetermined decision criterium.
 9. An apparatus according to claim 8wherein various parameter standards and information relating to adesired synthesizable respiratory pattern are stored in a memory (5) andare selectable in a program mode, during which the instruction signalgenerator (ii) is disabled.
 10. An apparatus according to claim 9,wherein memory (5) comprises a number of parameter standards andcorresponding respiratory pattern information.
 11. An apparatusaccording to claim 10, wherein respiratory pattern information relatesto the inhalation and exhalation times, the inhalation and exhalationrates and/or the pauses following the inhalation and exhalations of thedesired synthesizable respiratory pattern.
 12. An apparatus according toclaim 11, wherein when the starting signal is active, the instructionsignal generator (11) compiles in a feedback mode the desiredsynthesizable respiratory pattern of the respiratory pattern informationwhich the control device (7) reads from the memory (5).
 13. An apparatusaccording to claim 12, wherein it comprises an operating device (51)equipped with a key board (50), by which means switching betweendifferent modes, selection of the standards stored in the memory (5) andrespiratory pattern information and/or volume regulation of theinstruction signal (12) is possible.
 14. An apparatus according to claim13, wherein it is further provided with a display unit (52), by whichmeans current mode, the selected standards and the respiratory patterninformation and/or the instruction signal volume can be visualized. 15.An apparatus according to claim 14, wherein the display unit (52) in thefeedback mode also displays information sent by the processing device(4) concerning parameters of a currently recorded respiratory pattern.